An expansion of the first, it is a game of utter creativity and development. Yet, the concept seems to be losing steam.
It can be said that this series isn't meant to be played for the story mode. However, this is a good start to give you an idea of what you can create on your own if you're willing to put in the time. For me, honestly, I just don't have the patience to really make any levels worth playing but that doesn't mean the game isn't extremely well done.
At its core, LBP is more of a construction set for game making than a game proper. That is, once you finish the story the rest of your time is spent playing other people's creations and making your own. If you're a tinkerer or really into Minecraft this is a solid alternative to keep your creative energies going.
These guys do a marvelous job of making the creative process fairly intuitive though it can still be overwhelming just how much time it can take to make a truly awesome level.
If you put thousands of hours into the first game you'll likely do the same in this one. However, if you're not, you might not find as much thrills this round as you did in the first.